Principles of Engineering Physics 1 () || Holography

摘要： Electromagnetic radiation scattered by an object contains all the information about the object. In photography, distribution of only the intensities of light scattered from the object are recorded on photographic plates. It is a 2-D representation of 2-D or 3-D object; it gives only a single view. The term “holography” is derived from Greek by combining Holos (whole) and graphy (writing) meaning complete recording of information on images in terms of scattered intensities and phases. In holography, distribution of intensities of light scattered from the object along with is phases are recorded on photographic plates. It is a 3-D representation of a 3-D object on a 2-D sheet; it gives a 3-D view. Here three-dimensional images using coherent laser light are produced on photographic plates. Therefore, though holography was invented by Dennis Gabor in 1948 (it earned him the Nobel prize in Physics in 1971), it gained momentum only after the invention of the laser in 1960, the powerful source of coherent light. In this chapter, the concept of holography is presented very briefly.